Venous leg ulcers may have a high level of exudation. These wounds are often treated with a highly absorbing wound dressing such as foam dressing. Due to the underlying venous insufficiency the treatment is combined with compression therapy. The optimal dressing on these wounds should therefore be able to handle the exudation of the wound, but also be in compliance with the compression therapy.
Compression therapy is used to support the back flow of blood from the legs by applying an external pressure on the legs. When used in connection with treatment of a venous ulcer, this pressure also causes a pressure on the foam dressing and on the surrounding skin.
In general, foam dressings have a thickness of up to 6 mm. The pressure from the compression therapy on the foam dressing and the skin may lead to indentations on the skin. These indentations may be more or less pronounced depending on the degree of oedema in the leg and the dressing used. In severe cases, it has been observed that at the edge of the indentations, the skin deteriorates and a new ulcer is formed.
WO91/01706 provides a conformable wound dressing comprising an absorbent layer comprising polymeric foam, a wound facing discontinuous adhesive layer over one surface of said absorbent layer and a layer of a liquid impervious moisture vapour permeable material over the opposed surface of said absorbent layer wherein the thickness of the absorbent layer at two opposed margins is substantially less than the thickness of the absorbent layer between said margins.
The skin surrounding a venous leg ulcer may be extremely fragile. In order to avoid deterioration of this skin, adhesive foam dressings are not suitable for use.
Venous leg ulcers may, as earlier described, have high levels of exudation. As the non-adhesive foam dressing absorbs the wound exudate during the wear time, the absorption capacity of the foam may reach its maximum. When the maximum absorption capacity is reached, the absorbed wound exudate approaches the edge of the dressing. If the dressing is not changed in due time, the absorbed wound exudate may leak out from the edge portion of the non adhesive foam dressing to the ordinary stocking and/or the compression stocking causing discomfort for the user. In some cases, this may lead to maceration and creation of new venous leg ulcers, which is very undesirable.
Straight edges of the dressing may lead to indentations of the leg when the dressing is used in connection with a compression bandage.
Due to the reasons mentioned above, there is still a need for a non-adhesive foam dressing designed in such a manner, that the risk of leakage is minimised and the risk of skin deterioration caused by indentations from compression therapy is reduced or eliminated.
A high density at the edges would prevent leakage of wound exudate through the edge. However, this would further enhance the risk of indentations in the leg.
The present invention provides a solution to the above object by supplying non-adhesive foam dressing where the edge portion of the dressing comprises a bevelling with higher density than the central part of the dressing and a method of producing the bevelling.
By bevelling the edges and providing a higher density at the edges it is possibly to achieve a wound dressing which at the same time reduces the risk of leakage and indentations in the leg and where the wound dressing still has high absorption capacity.
The invention also provides a foam dressing having a bevelled edge with higher density than the central part of the dressing and where the backing layer extends all the way to the wound-contacting surface defined as the underside of the dressing designed to cover the wound, when the dressing is in use.